In general, it is an aspiration of the development of new motor vehicles and the further development of existing motor vehicles, in particular commercial vehicles, to reduce fuel consumption and the emissions of harmful substances and CO2. Besides the technical optimization of motor vehicles, such as the development of low-consumption and low-emission drive motors, efficiency-optimized multi-stage manual transmissions, tires with low rolling resistance, and streamlined vehicle bodies, truck drivers' cabins and truck bodies, a further possibility for reducing fuel consumption and the emissions of harmful substances and CO2 is to use the motor vehicle with appropriate control of the driving operation.
To save energy and costs and to reduce the burden on the environment, in suitable driving situations vehicles can temporarily continue moving ahead without drive-power, in so-termed rolling or coasting mode. In particular, in a motor vehicle in the rolling mode the internal combustion engine can be operated with as low fuel consumption and emissions as possible by idling, while the vehicle is rolling with its drive-train disengaged. If the internal combustion engine is switched off in such a driving situation in order to increase the saving effect still more, the vehicle moves in a so-termed coasting mode. These functions are already known.
Depending on the drive-train components present and the existing type of transmission, the power flow can be interrupted by shifting the transmission to neutral or by opening a starting clutch, as soon as a rolling mode or coasting mode is deemed possible.
WO 2016/007071 A1 describes a method for controlling an internal combustion engine of a motor vehicle. With regard to a future speed profile, it is established by simulation whether the motor vehicle can be operated in a coasting mode. Before the motor vehicle is operated in the coasting mode, various conditions are checked, which must be satisfied in order to authorize the internal combustion engine to be switched off.